1. Field of Invention
This invention is concerned with the display in color of variables presented as waveforms. It is also concerned with the combined display, for visual appraisal, of several quantities which are different functions of the same variable or variables. More specifically, it is concerned with the combined display of different seismic functions.
2. Description of Prior Art
In several branches of science useful conclusions can be drawn from variations of several quantities as a function of a common variable. One example is in seismic exploration, where the use of colors by geophysicists and geologists to display their interpretation of recorded or observed data in the form of geological cross-sections is known.
A color display adds certain computed quantities to the conventional black and white display. For example, a conventional black and white display shows a plot of reflective amplitude versus recorded time. By using color displays, frequency and velocity can be incorporated.
A particular method of forming color displays of seismic data is illustrated by U.S. Pat. No. 3,961,306, issued June 1, 1976 which is hereby incorporated by reference. The method comprises processing input seismic data to form a color assignment table of 40 colors for various ranges of magnitude of the positive amplitudes forming a first color component display for a first group of amplitudes, repeating this step to produce displays for a preselected number of additional colors, and superimposing the displays to form a color graphic display. The number of colors utilized incorporate multiple shades of the various colors.
More particularly, each oscillation of the prior art is divided arbitrarily into one or more partitions and each partition was colored according to a sample value or values falling within that particular partition. This resulted in oscillations having one or more colors, which could cause confusion in the analysis of the seismic display.